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3.
Tuno plate to resonance for m,ximum meter indication.
4.
Tune grid to resonance.
5.
Adjust neutralizing capacitors for a minimum feed-
thru of R.F. power.
AUTOMATIC RECYCLE OPERATION
With the transmitter operating properly,
all that is necessary
to place the transmitter in automatic recycle operation is to
place the " tune operate" switch in the " operate" position.
This places the recycle unit into the transmitter's control
circuit.
o
The recycle unit is described in a separate series of instruc-
tions which is a part of this instruction book.
The follow-
ing will take a typical transmitter malfunction and trace its
operations:
1.
The P.A.
amplifier plato circuit experiences an overload.
Relay K708 energizes and locks closed.
At the
same time
the plate overload indicator light will be extinguished.
2.
The primary auxiliary overload relay, K3 in the recycle
unit,
is energized by the contacts of K708 closing, which
perform three functions.
a.
It breaks the 240 volts a.c.
Circuits to the high
voltage contactors, K503 and K805 in the driver
and power amplifier control circuit.
b.
It applies 117 volts a.c.
to the time delay relay,
K4,
in the recycle unit.
c.
It also applies 120 volt d.c.
to R1 in the recycle
unit, which starts the recycle sequence.
3.
After an elapsed tine of approximately
3
seconds, relay
K3 again opens.
The overload relay which was previously
locked down and K708 also opens and relay K2 closes,
which in turn energizes the high voltage contactor coils.
If the overload is still present the same sequence of
operation will be again performed.
This will happen a
total of three consecutive times,
after which the trans-
mitter will remain off until it is reset and the over-
load cleared.
With the " tune- operate"
switch in the " operate" position,
the
following is the sequence of operation.
With the application of plate voltage on the driver, drive is
applied to the amplifier.
With the application of drive to amplifier, K702,
the grid
under drive relay is energized.
With the energizing of K702
6/22/61
-15-
FM- 20B
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